In our research programme the overall goal is to explore how residual stress/strain infulences thedeformation and fracture behaviour of engineering steels at high temperatures. Towards this goal, a crystal-plasticity based micromechanical model has been developed incorporating a significant number of grains. In-situ neutron diffraction (ND) tests at room and high temperatures have been carried out at ISIS. The work to be undertaken in this proposal aims to examine the in-situ lattice strain evolution of 316H stainless steel under cyclic loading at room and high temperatures.